Disable lazyload when downloading an offline page

This CL creates a bool in WebSettings to enable lazyloading of frames and images.
The bool is populated by WebContentsDelegate which offline pages listens to and
disables lazy loading.

Bug: 701884
Change-Id: I1ad1776adf3f9c7e6a8a3a68507aa9dc419e3955
Reviewed-on: https://chromium-review.googlesource.com/c/1352817
Commit-Queue: rajendrant <rajendrant@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Peter Williamson <petewil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612507}

chrome/browser/chrome_content_browser_client.cc

@@ -3207,6 +3207,12 @@ void ChromeContentBrowserClient::OverrideWebkitPrefs(
     }
   }
 
+  web_prefs->lazy_load_enabled =
+      (base::FeatureList::IsEnabled(features::kLazyFrameLoading) ||
+       base::FeatureList::IsEnabled(features::kLazyImageLoading)) &&
+      (!contents->GetDelegate() ||
+       contents->GetDelegate()->ShouldAllowLazyLoad());
+
   if (base::FeatureList::IsEnabled(features::kLazyFrameLoading)) {
     const char* param_name =
         web_prefs->data_saver_enabled

components/offline_pages/content/background_loader/background_loader_contents.cc

@@ -148,6 +148,10 @@ void BackgroundLoaderContents::AdjustPreviewsStateForNavigation(
   }
 }
 
+bool BackgroundLoaderContents::ShouldAllowLazyLoad() {
+  return false;
+}
+
 BackgroundLoaderContents::BackgroundLoaderContents()
     : browser_context_(nullptr) {
   web_contents_.reset();

components/offline_pages/content/background_loader/background_loader_contents.h

@@ -88,10 +88,10 @@ class BackgroundLoaderContents : public content::WebContentsDelegate {
   bool CheckMediaAccessPermission(content::RenderFrameHost* render_frame_host,
                                   const GURL& security_origin,
                                   content::MediaStreamType type) override;
-
   void AdjustPreviewsStateForNavigation(
       content::WebContents* web_contents,
       content::PreviewsState* previews_state) override;
+  bool ShouldAllowLazyLoad() override;
 
  private:
   friend class BackgroundLoaderContentsTest;

content/public/browser/web_contents_delegate.cc

@@ -300,4 +300,8 @@ std::unique_ptr<content::WebContents> WebContentsDelegate::SwapWebContents(
   return new_contents;
 }
 
+bool WebContentsDelegate::ShouldAllowLazyLoad() {
+  return true;
+}
+
 }  // namespace content

content/public/browser/web_contents_delegate.h

@@ -620,6 +620,9 @@ class CONTENT_EXPORT WebContentsDelegate {
   virtual void UpdateUserGestureCarryoverInfo(WebContents* web_contents) {}
 #endif
 
+  // Returns true if lazy loading of images and frames should be enabled.
+  virtual bool ShouldAllowLazyLoad();
+
   // Requests the delegate to replace |old_contents| with |new_contents| in the
   // container that holds |old_contents|. If the  delegate successfully replaces
   // |old_contents|, the return parameter passes ownership of |old_contents|.

content/public/common/common_param_traits_macros.h

@@ -240,7 +240,9 @@ IPC_STRUCT_TRAITS_BEGIN(content::WebPreferences)
   IPC_STRUCT_TRAITS_MEMBER(picture_in_picture_enabled)
   IPC_STRUCT_TRAITS_MEMBER(translate_service_available)
   IPC_STRUCT_TRAITS_MEMBER(network_quality_estimator_web_holdback)
+  IPC_STRUCT_TRAITS_MEMBER(lazy_load_enabled)
   IPC_STRUCT_TRAITS_MEMBER(lazy_frame_loading_distance_thresholds_px)
+  IPC_STRUCT_TRAITS_MEMBER(lazy_image_loading_distance_thresholds_px)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(blink::mojom::WindowFeatures)

content/public/common/web_preferences.h

@@ -320,6 +320,9 @@ struct CONTENT_EXPORT WebPreferences {
   // regardless of the actual quality.
   net::EffectiveConnectionType network_quality_estimator_web_holdback;
 
+  // Whether lazy loading of frames and images is enabled.
+  bool lazy_load_enabled = true;
+
   // Specifies how close a lazily loaded iframe or image should be from the
   // viewport before it should start being loaded in, depending on the effective
   // connection type of the current network. Blink will use the default distance

content/renderer/render_view_impl.cc

@@ -932,6 +932,8 @@ void RenderView::ApplyWebPreferences(const WebPreferences& prefs,
   settings->SetDataSaverHoldbackMediaApi(
       prefs.data_saver_holdback_media_api_enabled);
 
+  settings->SetLazyLoadEnabled(prefs.lazy_load_enabled);
+
   for (const auto& ect_distance_pair :
        prefs.lazy_frame_loading_distance_thresholds_px) {
     switch (ect_distance_pair.first) {

third_party/blink/public/web/web_settings.h

@@ -287,6 +287,7 @@ class WebSettings {
   virtual void SetDoNotUpdateSelectionOnMutatingSelectionRange(bool) = 0;
   virtual void SetMediaDownloadInProductHelpEnabled(bool) = 0;
   virtual void SetLowPriorityIframesThreshold(WebEffectiveConnectionType) = 0;
+  virtual void SetLazyLoadEnabled(bool) = 0;
   virtual void SetLazyFrameLoadingDistanceThresholdPxUnknown(int) = 0;
   virtual void SetLazyFrameLoadingDistanceThresholdPxOffline(int) = 0;
   virtual void SetLazyFrameLoadingDistanceThresholdPxSlow2G(int) = 0;

third_party/blink/renderer/core/css/resolver/element_style_resources.cc

@@ -31,6 +31,7 @@
 #include "third_party/blink/renderer/core/dom/element.h"
 #include "third_party/blink/renderer/core/dom/tree_scope.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
+#include "third_party/blink/renderer/core/frame/settings.h"
 #include "third_party/blink/renderer/core/html/lazy_load_image_observer.h"
 #include "third_party/blink/renderer/core/style/computed_style.h"
 #include "third_party/blink/renderer/core/style/content_data.h"
@@ -203,7 +204,9 @@ void ElementStyleResources::LoadPendingImages(ComputedStyle* style) {
             FetchParameters::ImageRequestOptimization
                 image_request_optimization = FetchParameters::kNone;
             if (!BackgroundLayerMayBeSprite(*background_layer)) {
-              if (element_->GetDocument()
+              if (element_->GetDocument().GetSettings() &&
+                  element_->GetDocument().GetSettings()->GetLazyLoadEnabled() &&
+                  element_->GetDocument()
                       .GetFrame()
                       ->IsLazyLoadingImageAllowed()) {
                 image_request_optimization = FetchParameters::kDeferImageLoad;

third_party/blink/renderer/core/exported/web_settings_impl.cc

@@ -711,6 +711,10 @@ void WebSettingsImpl::SetLowPriorityIframesThreshold(
   settings_->SetLowPriorityIframesThreshold(effective_connection_type);
 }
 
+void WebSettingsImpl::SetLazyLoadEnabled(bool enabled) {
+  settings_->SetLazyLoadEnabled(enabled);
+}
+
 void WebSettingsImpl::SetLazyFrameLoadingDistanceThresholdPxUnknown(
     int distance_px) {
   settings_->SetLazyFrameLoadingDistanceThresholdPxUnknown(distance_px);

third_party/blink/renderer/core/exported/web_settings_impl.h

@@ -204,6 +204,8 @@ class CORE_EXPORT WebSettingsImpl final : public WebSettings {
   void SetMediaDownloadInProductHelpEnabled(bool) override;
   void SetLowPriorityIframesThreshold(WebEffectiveConnectionType) override;
 
+  void SetLazyLoadEnabled(bool) override;
+
   // TODO(rajendrant): Remove these lazyload distance threshold settings for
   // frames and images, once the values are finalized from the experiment.
   void SetLazyFrameLoadingDistanceThresholdPxUnknown(int) override;

third_party/blink/renderer/core/frame/settings.json5

@@ -951,6 +951,10 @@
       initial: true,
     },
 
+    {
+      name: "lazyLoadEnabled",
+      initial: false,
+    },
     //
     // Lazy frame loading distance-from-viewport thresholds for different effective connection types.
     //

third_party/blink/renderer/core/html/html_frame_owner_element.cc

@@ -32,6 +32,7 @@
 #include "third_party/blink/renderer/core/frame/local_frame_view.h"
 #include "third_party/blink/renderer/core/frame/remote_frame.h"
 #include "third_party/blink/renderer/core/frame/remote_frame_view.h"
+#include "third_party/blink/renderer/core/frame/settings.h"
 #include "third_party/blink/renderer/core/html/lazy_load_frame_observer.h"
 #include "third_party/blink/renderer/core/html_names.h"
 #include "third_party/blink/renderer/core/layout/layout_embedded_content.h"
@@ -407,6 +408,8 @@ bool HTMLFrameOwnerElement::LoadOrRedirectSubframe(
 
   if ((RuntimeEnabledFeatures::LazyFrameLoadingEnabled() ||
        RuntimeEnabledFeatures::LazyFrameVisibleLoadTimeMetricsEnabled()) &&
+      GetDocument().GetSettings() &&
+      GetDocument().GetSettings()->GetLazyLoadEnabled() &&
       !lazy_load_frame_observer_ &&
       // Only http:// or https:// URLs are eligible for lazy loading, excluding
       // URLs like invalid or empty URLs, "about:blank", local file URLs, etc.

third_party/blink/renderer/core/html/lazy_load_frame_observer_test.cc

@@ -111,6 +111,7 @@ class LazyLoadFramesTest : public SimTest,
     settings.SetLazyFrameLoadingDistanceThresholdPx2G(500);
     settings.SetLazyFrameLoadingDistanceThresholdPx3G(600);
     settings.SetLazyFrameLoadingDistanceThresholdPx4G(700);
+    settings.SetLazyLoadEnabled(true);
   }
 
   int GetLoadingDistanceThreshold() const {

third_party/blink/renderer/core/html/parser/preload_request.cc

@@ -6,6 +6,7 @@
 
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
+#include "third_party/blink/renderer/core/frame/settings.h"
 #include "third_party/blink/renderer/core/loader/document_loader.h"
 #include "third_party/blink/renderer/core/script/document_write_intervention.h"
 #include "third_party/blink/renderer/core/script/script_loader.h"

third_party/blink/renderer/core/loader/image_loader.cc

@@ -100,7 +100,9 @@ bool IsLazyLoadingImageAllowed(const LocalFrame* frame,
       width <= kMinDimensionToLazyLoad && height <= kMinDimensionToLazyLoad) {
     return false;
   }
-  return frame->IsLazyLoadingImageAllowed();
+  return frame->GetDocument()->GetSettings() &&
+         frame->GetDocument()->GetSettings()->GetLazyLoadEnabled() &&
+         frame->IsLazyLoadingImageAllowed();
 }
 
 }  // namespace